W79E217A Datasheet, PDF (98/207 Pages) Winbond – 8-bit Microcontroller

Preliminary W79E217A Data Sheet
(RCLK,TCLK, CP/RL2 )= (0,0,0) & DCEN= 0
Figure 12-5: 16-Bit Auto-reload Mode, Counting Up
12.2.3 Auto-reload Mode, Counting Up/Down
This mode is enabled by clearing CP / RL2 in T2CON and setting DCEN in T2MOD. In this mode,
Timer/Counter 2 is a 16-bit up/down-counter, whose direction is controlled by the T2EX pin (1 = up, 0
= down). If Timer/Counter 2 is counting up, an overflow reloads TL2 and TH2 with the contents of the
capture registers RCAP2L and RCAP2H. If Timer/Counter 2 is counting down, TL2 and TH2 are
loaded with FFFFh when the contents of Timer/Counter 2 equal the capture registers RCAP2L and
RCAP2H. Regardless of direction, reloading sets the TF2 bit. It also toggles the EXF2 bit, but the
EXF2 bit can not generate an interrupt in this mode. This is illustrated below.
(RCLK,TCLK, CP/RL2 )= (0,0,0) & DCEN= 1
Figure 12-6: 16-Bit Auto-reload Up/Down Counter
- 98 -
Publication Release Date: December 14, 2007
Revision A3.0